Nginx not logging to socket

[Vladimir Homutov]

On Wed, Jun 24, 2015 at 10:21:06AM -0400, Danomi Czaski wrote:
> On Wed, Jun 24, 2015 at 10:00 AM, Vladimir Homutov <vl at nginx.com> wrote:
> > On Wed, Jun 24, 2015 at 08:31:31AM -0400, Danomi Czaski wrote:
> >> On Wed, Jun 24, 2015 at 7:03 AM, Vladimir Homutov <vl at nginx.com> wrote:
> >> > On Wed, Jun 24, 2015 at 06:12:49AM -0400, Danomi Czaski wrote:
> >> >> Hello,
> >> >>
> >> >> On Sun, Jun 21, 2015 at 8:19 AM, Andrew Holway
> >> >> <andrew.holway at otternetworks.de> wrote:
> >> >> > Hallo!
> >> >> >
> >> >> > Using rsyslog I have set up a logging socket and confirmed that its working
> >> >> > by piping in some stuff to "logger -u /dev/log"
> >> >> > nginx/1.8.0 does not seem to be dumping in logs however. The nginx config is
> >> >> > below..
> >> >>
> >> >> Any luck? I'm seeing the same problem on 1.7.12.
> >> >>
> >> >
> >> > do you see some errors in the local error log? If nginx is unable to
> >> > send data to socket for some reasons (check socket permissions, selinux
> >> > and similar), you will see errors in the local log file.
> >>
> >> My config looks like:
> >>
> >>     error_log  syslog:server=unix:/dev/log;
> >>
> >> The only error I see is that nginx can't open /var/log/nginx/error.log.
> >>
> >>     $ nginx -t
> >>     nginx: [alert] could not open error log file: open()
> >> "/var/log/nginx/error.log" failed (2: Unknown error)
> >>     nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
> >>     nginx: configuration file /etc/nginx/nginx.conf test failed
> >>
> >> Of course /var/log/nginx isn't there because I'm trying to use syslog.
> >> If I create /var/log/nginx, nginx starts and I'll see debugging logs
> >> there but nothing related to syslog problems.
> >>
> >> The permissions on /dev/log look fine:
> >>
> >>     $ ls -l /dev/log
> >>     srw-rw-rw-    1 root     root             0 Jun 24 12:41 /dev/log=
> >>
> >
> > did you try increasing log level?  If there are no errors, nginx will
> > not write anything to log in your case.
> >
> > you can add one more error_log directive and point it to some local
> > file with write permissions to check there for possible errors.
>
> Okay, I see messages going to syslog, I had to increase the log level
> as you said. Thanks.
>
> It seems like there _must_ be a file logger or nginx won't start. If I
> don't want any log file it looks like I have to do something like:
>
>     error_log  /dev/null emerg;
>     error_log  syslog:server=unix:/dev/log debug;
>

This is intentionally: syslog is not reliable and nginx by default will
write logs to files. And there is a simple workaround - you just found it
iself.